Can We Trust the Math? Correlation of Objective Postvoid Residual With Calculated Subtraction Postvoid Residual

Objective The aim of the study was to determine the accuracy of postvoid residual (PVR) by subtraction as compared with objective measurement by bladder scan or catheterization. Methods This is a secondary analysis of postoperative patients who underwent avoiding trial by retrograde bladder instillation. Fill volume, spontaneous voided volume, and PVR were objectively measured; PVR was also calculated. Pearson correlation compared PVR by subtraction versus objective measurement. We then defined postoperative urinary retention (POUR) at 3 different PVR values (100 mL, 150 mL, and 200 mL) to compare the sensitivity, specificity, and positive and negative predictive values of subtraction for detecting urinary retention at these 3 thresholds. Results Data were available for 155 patients after urogynecologic surgery. Median PVR by objective measurement was 46 mL (interquartile range = 11–146 mL). Median calculated PVR by subtraction was 10 mL (interquartile range = 0–100 mL). Objective measure and subtraction PVR values were strongly correlated (Pearson coefficient = 0.78, P
Source: Female Pelvic Medicine and Reconstructive Surgery - Category: OBGYN Tags: Original Articles Source Type: research